How to Date Your Best Friend's Brother
by Veterization
Summary: Stiles/Derek AU oneshot. Scott's brother Derek gets surprisingly hot when he comes back from college. Stiles, and his hormones, deal with this new development less than gracefully.


_A/N_: I do not own Teen Wolf.

* * *

When Stiles is six years old, he meets Scott in first grade when he loses his crayons on the second day of school and Scott valiantly offers up his own pack when Lydia Martin firmly refuses to share her pristinely unused blue crayon even though Stiles says three pretty pleases in a row. They play together on the jungle gym during recess after that, trading lunches because Stiles' father is still learning how to make sandwiches the way Stiles likes them after his mother dies and Scott's mother always forgets that Scott likes the chocolate pudding, not the vanilla.

Stiles comes over to Scott's house now and again after school because Scott's neighbor has a trampoline that they like to sneak onto and see how high their momentum will let them bounce, and while he's over, he meets Scott's older brother Derek.

He's clearly not the type of older brother that's actually a cool guy to have around, since he appears to be too mature to indulge in Stiles and Scott's whines for him to join them in playing hide and seek in the front yard's bushes and he locks himself in his room to brood in silence instead of helping Scott learn how to add. Apparently Derek is old enough that he knows not only how to add, but also how to subtract and multiple and even do _long division_, which is a far-off prospect that Stiles isn't sure he'll ever be able to master when he considers all the numbers that are involved.

Stiles is pretty sure that Derek is the type of boy who never read _Peter Pan_ and grew up too fast before he ever had a chance to enjoy the wonders of being a kid—whether this was a voluntary premature development or not, Stiles isn't sure—mostly because he has the aura of an adult and doesn't seem to know that his mouth has the ability to smile. He would like to ask Derek if this is what happens to all boys as they grow up, that they grow cold and sad and deflated and stop liking cartoons, but Stiles decides that his fear of Derek overrides his curiosity on if he'll eventually turn into the same boy who is too cool for Disneyland and watching _Spongebob Squarepants_on Saturday mornings in wooly pajamas. He's almost positive that Derek would be less than willing to answer his questions, considering that he glares at Stiles like he's the nuisance he would desperately like to find the off button to when he and Scott go thumping through the house playing cops and robbers with their sound effects at their loudest volume.

His childhood whirs by with Derek making only minor appearances in it, all silent and contemptuous appearances because even when he gets older, Derek is still too cool for Stiles, and Stiles doesn't mind. By the best friend clause, Stiles needs to always take Scott's side in any sibling quarrels that occur between the brothers, and he doesn't have any problem defending Scott when Derek doesn't ever take the step necessary to secure Stiles' camaraderie as his younger brother's best pal.

He figures that maybe Derek is just one of the Weird Ones, or maybe he's depressed like all the commercials say one third of the United States is and just needs a few medicinal pick-me-ups in his morning juice, or maybe he never got enough hugs when he was younger because that default grimace on his face doesn't exactly scream approachable to anybody that catches sight of his glum face.

So for the majority of his adolescence and even the uglier stages of his puberty, Derek isn't one of Stiles' problems. When Stiles turns sixteen and Derek gives into his mother's pleas to transfer to an in-state college closer to home and starts paying frequent visits to his childhood home, no longer an acne-prone sulking boy but rather the sex on legs that starts stalking Stiles' masturbatory fantasies, he officially turns into a problem.

* * *

The biggest issue in having a boner the size of an independent island nation for his best friend's brother is just that: Derek is his best friend's brother.

Stiles likes to believe that if Scott ever found out about the filthy things that run through his mind about catching Derek in the shower during one of his absences from the campus to visit home, Scott might pardon him for his completely inexcusable violation of the bros-for-life-code simply because he's been such a prime example of what an ideal bro should be to his best friend for the better part of a decade. He's been there for Scott when he needed advice on his first crush, and he was there when he was then brutally rejected by his first crush, and he always carries one of Scott's prescription inhalers in his backpack just so he can be the lifesaver everyone wants to be at one point or another if Scott has an asthma attack in the middle of PE.

So really, he's pretty sure he's allowed to have one measly little crush on Scott's brother after years of completely angelic best friend behavior.

The day Derek comes home from college is the day Scott sulks all through chemistry, as if the idea of sharing the house with his temperamental brother is a nightmare he thought he had shaken off when Derek first moved out into a dorm room. Stiles knows that Scott and Derek bicker like they need lines drawn between them at all times to keep them out of striking distance of each other even if they both mutually acknowledge that they would take bullets for each other if the time came that trouble would be bestowed on either of them, but Scott still sighs all through lunch at the prospect of having to spend a week in the company of his killjoy brother.

"Mom's going to make me hang out with him," Scott whines, half-heartedly chewing his fork. "Think she would believe me if I told her I was too busy applying for college scholarships?"

"Not in a million years, buddy," Stiles says, patting Scott on the shoulder. "If you want, I can come over lots to make it more bearable. Pretty sure if we turn up our video games loud enough Derek will just exile himself to the garage anyway."

When Stiles comes over after school, he catches sight of Derek's shiny car in the driveway and pulls his rickety Jeep right next to it. As proud as Stiles is that he didn't inevitably turn out as dead in the soul as Derek when he grew up, he realizes belatedly that the nice car is just one of many signs that shutting himself in his room to study clearly resulted in some rewards while all Stiles does is barely scrape through economics with his inability to focus on lectures and actually give the effort to do his homework adequately. He pats his Jeep on the dashboard when he and Scott slide from the seats and slip through the garage door.

When Stiles walks inside and catches sight of Derek, quietly lounging on the couch with a college textbook in his lap, and attempts to catalogue into his brain the sharp line of his chin, the slight accumulation of stubble on his jaw, and the killer muscles to mentally replay over and over again with relish, he tries his hardest not to whimper aloud.

* * *

Scott and Stiles disappear upstairs after Scott and Derek exchange rather curt greetings from across the living room under the pretext of having a mountain of homework to complete while Stiles gapes at Derek's eyes, which he swears were never that striking color in the past when he was just a gangly teenage boy. Scott is in the middle of pulling out his math homework and rummaging through a collection of rogue papers taking up space in his backpack to locate his calculator when Stiles decides he's going to be a terrible friend and excuse himself to the bathroom.

Except he walks straight by the bathroom and goes right downstairs, grabs a bottle of water from the fridge just so he'll have something to occupy his hands with, and stands right in front of Derek where he sits stationary on the couch.

"Hi," Stiles says, eloquently.

Derek looks up from his textbook.

"You've, uh, changed a lot since I last saw you. I remember, um. Less muscles. Do you work out now? I bet you're a one-armed push up guy, right?" Derek stares, rather blankly, just like Stiles is six again and Derek isn't willing to engage in a conversation with his brother's goofy friend. "Oh god, you do remember me, right?"

"Stiles," Derek says, and Stiles is glad he's at least made some sort of impression in the duration of approximately ten years on the boy who is now the hottest thing he's ever laid his eyes on. A few months ago he was still stuck in daydreams of taking Lydia to prom and making out with her behind the bleachers, and now all he can think of is ripping the shirt off of Derek's chest and biting his nipple a few times. He wonders if maybe now is the time to indulge in an existential crisis about his blossoming homosexual tendencies.

"—thing?" Derek is saying, and that's when Stiles realizes that Derek was actually talking when he was slowly zoning out into thoughts of making out with Derek in Scott's bunk bed. Scott should probably take his World's Best Friend mug back.

"Uh, what?"

"I said, did you need something?" Derek repeats, sounding slightly annoyed. It's the same aggravated tone from Stiles' youth whenever Stiles would knock on his tightly locked door to beg for Derek to come play hide and seek tag with him and Scott because it's much too boring with only two kids who always burst into giggles when they're about to be discovered in their hiding spots and Derek would promptly refuse, except the timbre of his voice has gotten significantly lower and rumbles more. He doesn't know when Derek got _so grown up_when he wasn't even looking, with the rough, dark stubble dotting his cheeks and the broad, manly palms.

"Uh, no," Stiles says. "Just wanted to welcome you back home and all. It's good to see you back again, even if you probably still wouldn't play hide and seek with me and Scott."

"No," Derek deadpans, and Stiles chuckles nervously before stumbling over his own feet climbing up the stairs again. It's like when he's looking at Lydia and slurps half his meal down his shirt, except this time he's not ogling impressive cleavage or flawless strawberry blonde curls, but rather a strong set of shoulders and slender fingers that probably learned all kinds of tricks at college.

He supposes that there's one good thing about having a crush on his best friend's brother. His best friend's brother will absolutely never have a crush on him too.

* * *

Stiles is on the side of the road thumbing a criminal piece of scrap metal between his fingers that is responsible for deflating his rear tire when Stiles sees Derek next, pulling off the road and stepping from his car like a knight in shining armor.

The Camaro shimmers, ironically, just like knight's armor when it rolls to a stop on the gravel right behind Stiles' crooked Jeep, tilting on his deflated tire like a lopsided, limping child, and out steps Derek right when Stiles is about to give in and call his father about his emergency on the side of the road that leads to the Dairy Queen that he was hoping to enjoy a chocolate smoothie from. He's still desperately trying to understand why changing a tire isn't a necessity on the driver's test when Derek kneels by him and takes in the sorry sight of his car.

"Amazing how you how still haven't gotten rid of that habit of getting yourself into every instance of trouble that presents itself," he says, sounding less irritated by Stiles' clumsiness and more fond than Stiles has ever heard before, nothing but an undercurrent of amusement tinting his words, and Stiles watches in awe as the sun shines on the left hemisphere of his face and illuminates his cheekbones in a way that should be illegal. He's sixteen, dammit, and should be able to control his nether regions at the sight of an attractive face, and when that line of thinking does little to quell the stirring in his pants, he fixates his brain on Coach Finstock naked, eating moldy cake, and the idea of Scott having sex. It does the trick.

"My father tried to have it surgically removed, but turns out I'm stuck with it," Stiles jokes feebly while Derek props the car up with a jack he produces from the crook of his elbow.

"Where's your spare tire?" Derek asks suspiciously after he's done with the jack, peering into his trunk and rifling through a few empty beer cans that Scott and him left hidden in the back of his car when they decided to get mutually wasted on a hot July night and various CDs peppered on the flooring.

"Uh, not sure? I think I might have lost it. Or maybe the car didn't come with one. I'm driving completely illegally without having one, right?"

"Are you sure you're old enough to drive?" Derek asks, and wow, Stiles has never felt so much like he's advocating pedophilia in his life. He frowns hard and gets to his feet.

"I'm _sixteen_. I'm not that much younger than you."

"Really? Because I vividly recall days when you were still eating dirt from the backyard and couldn't reach the kitchen counter," Derek snorts and closes Stiles' trunk again. Once again, Stiles feels like he's seven years old while Derek acts like the only veritable adult in the room. He stalks up to Derek and takes personal pleasure in the fact that they're pretty much the same height now with the exception that Derek's hair is insanely full and ruffles into the sky. Stiles wonders if it's soft.

"Dude, the only difference between you and me is that you have the maturity of an old Asian monk—"

"Get in my car," Derek interrupts him without a single care that Stiles was in the middle of extensive rambling, and cocks his head to his Camaro. It's still unfair that Derek proves that even if all work and no play makes Derek a very dull boy, it still means he can afford the nicest car in Beacon Hills.

"And out of my dreams?"

"What?" Derek grumbles, and settles into the driver's seat while Stiles follows him. "There's not much I can do for your car if you're missing your spare. I'm calling a tow truck and taking you home."

Being in Derek's car would have been extremely awkward if this was six years ago when Stiles had the steadfast obligation to ignore Derek to uphold his loyalty to Scott, not to mention that back then Derek had absolutely nothing going for him considering that he was a scrawny kid with no social skills and Stiles was fairly frightened of his shadowy demeanor when his brother was the complete opposite in everything from eye color to personality to academic prowess, but now all Stiles sees is that he's in a hot car with a hot dude being driven around like they could get it on in the backseat at any time. The car smells like leather and a musk that Stiles realizes is the nearly intoxicating scent of Derek's cologne, and really, it's unfair that anyone should be able to go through puberty this seamlessly.

Derek calls for a tow truck and starts the car with a smooth purr before sliding to the road, where naturally, the car runs like it's driving over clouds in comparison to Stiles' car which he knows he can't drive over forty-five and might not have enough motivation in it to make it up steep hills.

"So, Derek," Stiles says casually while he fiddles with the radio and Derek swats his hand away like it's a fly buzzing in his food. "How's college life?"

"Fine," Derek says, and doesn't bother reciprocating and warmly asking Stiles how high school has been treating him, which is a shame, because Stiles could easily begin chatting about how amusing the girls think he is and how charming he's become even if it's a flat-faced lie.

"And your dorm? Got a roommate?"

"I asked not to have one. I need room to work out and having a roommate clogs things up."

"So it's just you?" Stiles persists, and Derek gives him a glance out of the corner of his eyes before flickering back resolutely to the road. "Never have any hot chicks in your bachelor pad?"

"How about we play the quiet game, Stiles, since you love games so much?"

Stiles opens his mouth to assure Derek that no, he doesn't play hopscotch and Marco Polo under the porch anymore, but decides against it when he realizes that Derek is parking outside his house and that Scott is staring incredulously from where he's shooting hoops in the driveway when he sees Stiles secured in the Camaro's passenger seat.

"Huh," Stiles says, and smiles.

"What?"

"Just thought that when you said you'd be taking me home you'd bring me to _my_home."

He looks over at Derek, who is staring fixedly at the steering wheel and is in the middle of furrowing his eyebrows as far as they can be knitted together into one singular, angry eyebrow, and is about to jab him playfully in the ribs when Scott drops his basketball and raps his knuckles on the window.

"Oi! What are you driving around my best friend for?!"

* * *

Stiles spends his next chemistry period being productive by not pretending to read chapter seventeen and taking thorough notes but rather creating a pro-con chart in the margins of his notes next to a few dolphin sketches as to why it would be and would not be a good idea to go out with Scott's asshole older brother.

PRO:

-Derek is kind of hot

-Would like to see the guy naked

-Would like to have mind-blowing sex

-Hiding from Scott could be pretty arousing

CON:

-Derek would eat me alive if he knew that the majority of my wet dreams now consist of the sizable bulge in his jeans

-Pretty sure Scott would kill me

-Pretty sure Scott would team up with his mother to kill me

-Slight homosexuality crisis

-Mild pedophilia concern (dad might be super concerned too, ergo: police will be concerned, ergo: boyfriend goes to jail, ergo: I get a reality show on TV)

Stiles stares down his pros and cons like they hold the answers to life if he focuses on the scribbles long enough, chewing on his pencil all the while. He ends up thoroughly considering each reason until he gets hung up on the idea of getting frisky with Derek in the pantry while Scott pads around in the kitchen looking for snacks and forces them to keep quiet even though clearly, Derek would be a dirty talker through it all. He's still in the midst of rifling through other scenarios in which he and Derek ultimately end up romping around in each other's pants when Mr. Harris grabs his notes, catches sight of the dolphins, and promptly crumples up a whole period's worth of hardcore thinking and tosses it into the trashcan.

* * *

When Scott meets Allison Argent, all that is holy and right in the world presents itself on Stiles' plate.

During any other occasion, he would probably be irked that Scott is so willing to blow off his best friend for a girl he's been fawning over for a total of two hours, but under the circumstances that Derek spends his evenings studying for midterms in the living room like prey waiting to be mauled and made out with until both he and Stiles sound like they've just left dental surgery, Stiles doesn't mind when Scott pleads to turn their Friday night video game bonanza into a help-get-Scott-look-spiffy-for-his-date event.

When he comes over, Scott and Derek are actually working together in surprising harmony, consisting of Scott whining impatiently while Derek gives him aftershave advice. Scott looks like the epitome of a nervous high schooler going to homecoming, beads of sweet gathered on his forehead and fingers trying desperately to smooth back the wayward strands of his hair. He looks incredibly young and borderline foolish considering how much he's sweating over the prospect of one date, and Stiles hopes to god that Derek doesn't view both his brother and his dorky friend as the same childish cartoon of a person.

Stiles fulfills his best friend duties pretty well after he gives gentle criticism on Scott's orange jacket and then gives him various tips he learned from the _Seventeen_magazine he snatched from the doctor's office that told him to always keep a mint handy in his pocket and not mention her weight no matter how she looks in her clothes, and after he marshals Scott out of the door he knows he's free to go, especially since Scott's mother isn't always thrilled to see Stiles hanging out eating her son's potato chips when she comes home from a late shift at the hospital, but instead he takes the golden opportunity dangled in front of him and decides to approach Derek.

"Whatcha reading?" Stiles asks, situating himself on the seat next to Derek on the couch. The spine of his tome reads _Mythology of Lycanthropy_and is readily visible to Stiles, but he still waits patiently for Derek to answer him.

"Just some light reading for class," Derek murmurs, turning a page. He doesn't look up from the words, clearly uninterested in whatever conversation Stiles is ready to strike up, but Stiles doesn't heed the signal.

"Werewolves, huh? Maybe if you'd go backpacking through London you might become one."

That earns him a raised eyebrow over the pages of Derek's book. Stiles takes the contributory emotion and runs with it, especially because it conveys poorly veiled confusion and means Stiles is actually capable of teaching the college student facts about the cultural media.

"What?" Derek asks, and his interest sounds slightly piqued, which Stiles will gladly take as a mild victory.

"Are you telling me you've never seen _An American Werewolf in London_? Really? _The_ classic werewolf movie that will probably teach you more than that dictionary-sized book will? Are you going to tell me you haven't seen _Star Wars_either after that?"

"I haven't seen _Star Wars_," Derek deadpans, and he doesn't even sound a little bit like he feels that a part of his childhood has gone horribly wrong. Stiles feels like he's looking at a depraved child who clearly suffered more than just lack of social etiquette when he locked himself up in his room for years when he was younger, but an entire chunk of movie marathons that are a requirement in order to graduate from childhood. He remembers being in junior high and bonding with his father over Luke Skywalker's plight while they passed popcorn back and forth and Stiles didn't even bother admonishing his dad for buying the extra buttery kind, and wonders if Scott and Derek would have ended up being closer brothers if they had manned up and watched some Disney classics or Indiana Jones together when they were younger.

An hour later, somehow, Stiles is no longer checking his phone to see if Scott is updating him on his date with Allison, but is instead camped out on the living room floor setting up _An American Werewolf in London_ on the DVD player with Derek leaning against a pillow beside him. It sort of baffles Stiles that it took him more than ten years of knowing Derek to know him as anything but the label _Scott's brother_and to actually spend quality time with him, even if he won't know a thing more about the guy after the credits roll. He wonders if Derek too believes it to be terribly overdue, because if for nothing else, he should have at least scoped Stiles out when he was a child to make sure that Scott wasn't getting mixed up with juvenile delinquents and securing hooligans as friends.

They watch the movie in general silence, except Stiles is still positive that Derek is one of the best audiences to bring along to the theater when the movie finishes. His breath hitches now and again during a climatic scene and his eyebrows furrow in disgust whenever there's gore, tiny expressions and reactions that make Stiles proud to have shared a classic horror story that no one else has ever bothered to show Derek before.

The best part is surely when Derek leans over halfway through the movie and tries to, as casually as possible, whisper in Stiles' ear, "David knows he's a werewolf that committed those murders, doesn't he?"

Scott comes home nearly at midnight to ramble endlessly to Stiles about how sweet Allison smells and how addicting the sound of her laugh is, and Stiles nods along while he replays in his head the way Derek's knee would occasionally bump against his while they passed the microwave popcorn back and forth.

* * *

The next few days, Stiles whips out every excuse he can think of in order to hustle over to Scott's place after school, ranging from the classic we-have-a-very-important-science-project excuse to hand to his skeptical dad to the just as classic I-could-whip-your-ass-in-Grand-Theft-Auto taunt that always has Scott setting up dates and times for their next video game battle.

He feels only slightly bad, deceiving his best friend into thinking that he really likes his face so much that he feels the need to see it every hour of every day when he does, in actuality, have his own house that stores its own food and has his very own father living in it, but then he thinks of Derek and how visits to home are exactly that—nothing but _visits_—and how his time is limited each time Derek makes the trek over from campus in order to woo the broody devil into his arms.

So far, the plan hasn't been going precisely as he had imagined, but Derek says more words to Stiles in one week than Lydia has said to him in his entire school career, so he considers that a plus in his charisma and his attempt to woo his best friend's brother.

Stiles can't let himself think about it too hard. When he focuses on the fact that Derek and Scott are always a hall away and share the same bathroom and have spent road trips wailing in the back of cars together because _they are brothers_, the guilt starts setting in like mold on a bad bag of apples, and nobody likes a rotten apple, so Stiles focuses on other things rather than Scott's family tree and the very short line he has to draw in order to get to Derek from Scott. He thinks that one day, he might suffer for this in the special hell, but until then, he might as well find a way to deserve a trip to the pit.

He learns more about Derek in one week than he has in a decade of knowing Scott's family, which is bizarre considering that they've all been camping together and Stiles once spent three weeks straight at Scott's house in the summer of '08 indulging in an Oreo binge and a Batman marathon that resulted in a serious drop in both of their hygiene for the better part of twenty-one days. He supposes it's because this time around, he's actually putting in the effort to learn who Derek is. He doesn't learn the life-changing, tragic stuff, like Derek's worst memory or what his greatest fears and goals are, but he learns little things that Derek lets slip, like the fact that he didn't take up weight-lifting until he got to college and that he's since learned to cook when he discovered just how rancid the dormitory cafeteria food is, or that his hidden talent is that he can kick ass playing video games because studying and sulking wasn't all he was doing when he shut himself in his room years ago.

"You're kidding," Stiles says when Derek lets that piece of information slip, jaw open. Derek taps it closed with his thumb. "I don't believe it."

Derek shrugs, something like poorly hidden pride flitting over his face. Stiles howls in delight at the idea of Derek squatting in front of a television with controllers in his hands while he races for the best high score, and that's how he finds himself situated in front of Scott's Xbox fifteen minutes later with Derek promising to beat his ass into the next universe.

"You couldn't beat my ass if you tried," Stiles says, and then promptly decides to stop imagining Derek and his ass in the same situation. "Like brother, like brother, I'm betting, and Scott's hand-eye coordination is in the toilet."

Ten minutes later, Stiles' foot is in his mouth when Derek really does kick his ass into the next universe and the television boos loudly at his pitiful score.

* * *

Beating off in Scott's hall bathroom while Scott rummages through his stack of video games looking for his missing Call of Duty case, Stiles will admit, is not his finest moment.

He blames Derek, who was walking around shirtless after he mowed the lawn and then proceeded to do sets of crunches in the grass because apparently, in between the miracle transition from skinny boy to a man who could easily be the subject of a Grecian sculpture, Derek took up rigorous exercise routines. After Derek started walking through the hallway looking for a change of clothes and poking his head into Scott's room to let him know that there were leftovers still up for grabs in the kitchen, Stiles found it pretty hard to focus on saving Princess Peach in Mario Kart and then endured a fifteen minute glory speech of Scott celebrating his video game triumph.

He tries not to concentrate on exactly how many times Scott would punch him in the face if he knew that his best friend was jacking off in his bathroom to the thought of his brother bending him over the bathroom counter and licking him open for his cock, and decides to momentarily blame his weakness on the fact that he's a horny sixteen-year-old boy who has zero outlets for his sexual frustration with the exception of his right hand and that everyone has needs.

It doesn't help that the bathroom actually smells like Derek, like he dabbed off some of his sweat from trimming the lawn in the sun with a few towels, starting to fuel and awaken some of Stiles' hormones that he never even knew existed. He braces his free hand on the toilet and looks steadfastly away from where Scott's deodorants are laying on the counter beside the sink, determined not to bring Scott into his fantasy to officially cockblock the idea of Derek going down on him, Derek fingering him open the way he never can with his own fingers when he slicks up with shampoo suds in the shower, or Derek's hand wrapping around his length to jerk him off while he whispers obscenities in his ear.

Stiles' eyes flutter closed and he lets Derek's name softly fall from his lips while a wall away, he hears Scott cursing while he paws through the piles of dirty clothes under his bed to find his lost game. He blocks out Scott's swears and focuses instead of the sound of Derek clearing his throat or the way he glares at Stiles—just like how he used to do it when Stiles the six-year-old annoyed him while he was busy, except now it's unbelievably hot—and speeds up the tempo of his hand, flicking his wrist.

His erection hardens at the images and blood rushes south at the idea of letting his hands roam over a chest larger and more defined than his own, and wow, Stiles never thought he'd be into college dudes when there are plenty of fish to choose from in the swamp that is his school, but he goes with the flow as another wave of arousal crashes through him like fog and has his finger thumb the slit on the head of his cock. He bites to lip to keep his groans at bay, and god, this is not what best friends do to their best friends _at all_—

There's a knock on the door, but Stiles barely hears it, barely even processes it when all that's running through his brain on repeat like a broken record is _stroke stroke stroke_ while his hand alternates between squeezing and pumping the base of his erection while various thoughts of _Derek_, all of which include him being either naked or in the middle of making Stiles so, swim through his mind like hot, wispy apparitions. The knock comes again louder than before, and before Stiles can so much as consider pulling up his pants and making himself seem presentable, the door opens.

He can't _believe_that of all things, he forgot to lock the door.

It's not Scott and Derek's mother, thank the cosmic deities that are probably in peals of laughter at the sight of Stiles' humiliated cheeks burning up like they're being assaulted by bouts of prickly fire, and it's not Scott either, who probably wouldn't be able to look Stiles in the face for a good two weeks after getting a front row glimpse of his Unmentionable Place considering they're in that phase of boyish wannabe manhood where touching your best pal for longer than two seconds might as well be a five minute embrace with ass groping. But somehow, despite all of those possible outcomes flitting in front of his eyes like flashes of nightmares, he's pretty sure he would have taken either instead of having Derek walk in on him.

It all goes bad so very quickly, except for his dick, which is not at all dismissed at the interruption nor does it wilt at the sight of Derek's face, suddenly tinged pink on the cheekbones and lips parted in a perfect, shocked _o_that would be terribly arousing at any other point in time. He wonders how much Derek's seen, how much he's inferred, or if he could still desperately pass this off as taking a long piss, but he takes too long to even come up with adequate excuses because the next thing he knows Derek's throat is releasing a sound akin to the needy whine of a hungry bear.

"_Stiles_," Derek says, eyes flickering down to where Stiles' pants are pooled at his ankles before he firmly addresses the ceiling. It's the strangest thing, to see what appears to be an ugly mixture of utter embarrassment along with unveiled shock and maybe even some other emotions blended in for good measure all splayed for the world to see on Derek's usually passive face, but before he can apologize or groan or invite him to join the party, Derek is slamming the door shut and is thundering down the hall so quickly it sounds like the Hulk is storming away with the hustling attitude of someone who wants to get the hell away.

* * *

Getting drunk, Stiles thinks, is a staple of being a teenager who's not out on a date at the nearest bowling alley on a Friday night. However, getting wasted to the point where he feels like the stars are moving under his feet and orange construction cones on the side of the road are gangs of tabby cats is probably just a bad idea.

He has no idea when he lost Scott. He remembers hanging out in the Beacon Hills Preserve with his best pals, Scott and a bottle of Absolut, when suddenly he teleported magically to a cul-de-sac with Scott nowhere in sight. He takes a moment to marvel at his own teleportation skills when he realizes that he probably swayed and stumbled all this way here on his own two feet but was too busy trying to get the pitch of _Bohemian Rhapsody_right to focus on his footwork, and then starts doing what any respectable intoxicated gentleman would do and starts calling out Scott's name.

"Scotttttt," Stiles whines, and makes sure to yell so it makes it into the crevices of everybody's gardens and wakes up everybody's dogs. He slurs a bit on the extra t's he adds and walks directly into a mailbox. He spends a good minute laughing over the encounter before he pats the mailbox good-naturedly and meanders on.

He's still walking aimlessly down the middle of the street calling for Scott to appear before him, and really, he needs to put Scott on a leash when the guy is so prone to being lost and can't be accounted for when he downs half a bottle of heavy vodka, when an arm snakes around his waist and a palm covers his mouth.

He screeches and licks because he's pretty sure he's about to be kidnapped, but then he realizes that Derek's hardly amused face is looming over his while he shushes him in a no-nonsense tone until Stiles eventually stops thrashing. Slowly, Derek pulls the hand away from Stile's mouth and wipes his palm, now thoroughly covered in Stiles' saliva, on his jeans.

"What the hell is this?!" Derek demands. Stiles is ready to swear on his life that it was Scott who stole the last cookie. "I'm going to kill you! You're about to wake up the whole street!"

Stiles ignores him. "I'm pretty sure your brother ish missing, and he took all the booze with him," he slurs to the street at large, and is promptly quieted with a palm clapping over his mouth once more.

"You're sixteen," Derek deadpans, not at all entertained at the idea of Stiles or his younger brother sneaking liquor into the woods to get thoroughly plastered and bond with the wildlife while under the influence of heavy alcohol. "And Scott is too."

"'M not too young for you, sugar pumpkin," Stiles assures him, and that's when Derek rolls his eyes and slings Stiles over his shoulder like a sack of potatoes.

It's hardly comfortable and Stiles squeaks with every step Derek takes as he walks with a hasty purpose to a house that looks mildly familiar from where Stiles is looking at it upside down from his position of being slung over Derek's shoulder, and that's when he realizes that his instincts are _awesome_because his feet managed to bring him all the way back to Scott's house without his brain needing to provide assistance at all.

"Hey," Stiles says while blood rushes to his head and makes the world just a little bit blurrier. "My dad is not going to hear about this."

"I have a better mind to tell him," Derek grumbles when he opens the front door and manhandles Stiles off of his shoulder and into the house. Only a few lights are on, like the reading lamp by the couch and the oven light in the kitchen, and Stiles' retinas thank him for the lack of intrusive light.

"You wouldn't," Stiles gasps when Derek sets him back on his feet, lifts him by the armpits, and herds him in the direction of Scott's room like a farmer ushering cattle into a pen. Scott is mysteriously missing from the mayhem of crumpled papers and dirty laundry, and promptly Stiles falls on the bed. The mattress squeaks below him.

"You reek," Derek tells him bluntly. "Do you need water or do you need to throw up?"

"Scott—Scott ish lucky to have you as a brother," Stiles tells him solemnly. With the current state of his head, it feels like he's looking at two Dereks, both of them wavering over the bed. He swipes at one of them and manages to secure a handful of fabric in his hand and yanks. Derek obediently sits on the bed. "Don't have a brother."

"I know."

"You know shtuff about me?"

"Too much, frankly," Derek grumbles, trying to wrangle the sheets out from underneath Stiles' squirming body to tuck him in. Stiles sits up defiantly and feels a whiff of cologne, Derek's scent, waft up his nostrils. He grins.

"Schmell good," he tells him, promptly burying his nose in Derek's neck. Derek goes rigid under the face heartily sniffing at his collarbones. "Heyyyyy. I have a great idea."

"Does it involve you sleeping off whatever drinks you managed to pilfer for tonight?" Derek suggests, sounding rather clipped. Stiles lets his hands ghost up Derek's side while he tenses, nothing but defined torso under his fingertips. He chuckles and grabs hold of Derek's forearms while he nuzzles his neck.

"Actually, I thought we could do it in Scott's bed," Stiles giggles wildly. "I am _sho_making the naughty list this year."

Derek tenses up like a sheet of metal at Stiles' words, muffled into hot breaths onto the expanse of his neck, and grabs firm hold of Stiles' shoulders as if to still him from coming any closer even though Stiles is in the process of wrapping himself around Derek like a clingy piece of seaweed.

"Stiles," Derek says, and tries again when Stiles starts sloppily licking stripes up to Derek's ear. "_Stiles_, you have absolutely no idea what you're doing."

Stiles whines when Derek's grip tightens on his shoulders as a clear sign of a warning or possibly even a symptom of his own poorly-executed self-control, and Stiles whines again. He feels like he's six once more, begging for Derek to play hide and seek with him and Scott, trying to push at least a hundred more _e_'s into his _please_to make it more irresistible, and Derek is once again denying all things fun. He wonders idly if Derek ever has fun and takes that as his cue to palm Derek's crotch.

He earns a sharp hitch in Derek's breath when he does so, thumb tracing the seam of Derek's jeans when Derek's hand closes on his wrist and guides his hand away, even though it feels like it's taking every ounce of his restraint to do so. Stiles wonders if on some level, this is a victory, but then that thought promptly gets washed away in the waterlogged, alcohol-saturated pandemonium that is his brain.

"_Dereeeeeeeek_," Stiles whimpers, writhing on the bed sheets when Derek pushes him firmly down onto his pillow to a safe distance away once more.

"You need sleep," Derek says resolutely while he takes large strides away from the bed, and it sounds a bit like he's convincing both himself and Stiles of his own words. He turns the lights off and, almost compulsively, wrestles the blankets up to Stiles' chin before he disappears out the door like a ghost.

Even with his hard-on, Stiles falls prey to the alcohol and falls dead asleep in under two minutes.

* * *

Come morning, there is a large bowl acting as Stiles' emergency vomit bucket sitting unexplainably on Scott's bedside table along with a glass of water and two aspirin like the hangover fairy took the liberty to visit him while he was deep in the arms of intoxicated slumber, Derek is nowhere to be found, and Scott is buried in a bowl of cereal in the kitchen downstairs where all the blinds have been aggressively shut.

Stiles stumbles down the stairs and is wordlessly offered the same bowl of cereal in which a handful of soggy Cocoa Puffs are floating around in a milky abyss while Scott rubs uselessly at his temples.

"Dude, you're never going to guess where I woke up this morning," Scott tells him ruefully, but there are pieces of wildlife and a twig stuck in his mop of untamed hair, so Stiles has a pretty good guess.

* * *

The next time Stiles catches Derek alone, he's packing up a handful of jeans and sweaters into a duffel bag marking the end of the college's fall break and the start of another few weeks where Stiles totally doesn't count down the days until Derek's next visit and totally doesn't hope that Derek won't find an attractive teacher's assistant to start doting on and bring home to his mother to coo over. Stiles catches sight of Derek stuffing toiletries into his suitcase out of the corner of his eye when he wanders down the hallway, and despite his better judgment, goes to investigate.

"Are you leaving already?" Stiles asks, hanging in the doorway. Derek nods, pushing a few textbooks into his bag. "Feels like you just got here."

"I'm sure Scott's relieved he'll have his bathroom to himself again until Thanksgiving," Derek says with a wry smile.

"You're coming back for Thanksgiving?" Stiles says, and when he grins Derek gives him a funny look, like this is hardly the sort of thing Stiles should be excited about. Stiles tries to disguise his excitement through the façade of being exuberant about the turkey and the general lack of hungriness that follows for the next two weeks where all families eat nothing but turkey sandwiches until Christmas.

"Planning on it."

Derek ends the sentence there, not bothering to keep it alive. Stiles swings back and forth in the doorway and decides to fuel it himself.

"So do you like college life, you big party animal?"

"Stiles, do you need something?" Derek asks curtly, expertly bouncing over his inquires, not in the least interested in sharing tales of fraternity mishaps or beer keg stunts. Stiles figures that Derek probably has the partying spirit of a handicapped elderly gentleman, like the type he sometimes sees serenely playing chess with themselves in the park, and really doesn't need an answer to his question anyway.

"Uh, just wanted to say goodbye. Till next time, anyway. And when that time comes we'll both be so full with poultry we won't talk for probably three days straight," Stiles chuckles. Derek zips closed his bag and gives him another glance, like he's slightly surprised that Stiles is actually putting effort into awarding Derek with a goodbye instead of just patting him on the back and sending him on his way like Scott does.

"I guess we'll see," Derek says. "Bye, Stiles."

Stiles nods and is about to leave when he decides to drum up some inner courage probably stolen from a man with more audacity than he himself rightly possesses, taking a step out of the doorway to grab Derek's shirt in his fist and pull him into a kiss, reveling in the fact that Stiles doesn't have to lean upwards in order to press their mouths together.

It's a short kiss, still tinged with the residue of Stiles' nerves and slightly off-center, and Derek is the one to break it when he grabs Stiles' forearms and firmly pushes him into a more agreeable distance, his eyes wide. He looks like he's stuck in between having almost expected Stiles to kiss him sooner or later to revering in the awe that comes with having just kissed his brother's best friend. It's not like it was a spectacular kiss, lacking all sense of passionate tongue and clawing hands, but Derek still seems rather lost for words for a good few seconds while he surveys Stiles' face.

"Stiles, you're sixteen," he growls, voice rough like he's just downed a bottle of whiskey, and it burns pleasantly up Stiles' limbs like tingles of budding arousal. He knows that what Derek's saying is more of a rejection than an encouragement, and as son of the town sheriff Stiles should probably heed said warning, but instead he feels a resolution that is most probably his signature Stilinski stubbornness rise to the surface. He grabs hold of Derek's hips and doesn't let himself be guided away.

"Well observed," he says cheekily, and decides to bite down on Derek's earlobe for no other reason beside the fact that it looks like it's waiting to be bitten. "Anything else you'd like to add?"

Derek mutters something that sounds more like an internal struggle than anything else before a pair of strong arms wraps around Stiles' waist and all but lifts him from the floor, mouth hungrily finding Stiles' lips in a rough kiss and tongue begging for entrance at the seam of his mouth. Stiles whimpers and clings on for the ride, opening his mouth and trying his hardest to ignore the jump of his dick in his pants when their tongues first brush, hot and sweet, before Derek pulls away again, a clear fogging of lust in his eyes.

"More of that, please," Stiles begs, only slightly incoherently, and Derek reluctantly releases his hold on his waist.

"No," Derek denies firmly. "Scott is two doors away and you're—"

"—_don't_say sixteen, you big old man—"

"—never going to come up for air if I don't let you go now," Derek finishes without a breath, steamrolling over whatever complaints Stiles verbalizes. His hands clench and unclench on Stiles' hips like he's still unsure if walking away is the best choice his brain has ever made or the worst his libido ever has, and with one more blinding kiss that leaves Stiles astonishingly boneless under his ministrations, he wiggles out of Stiles' grasp.

"Um," Stiles calls out helplessly when Derek touches his lips and grabs his duffel with a newfound vigor. "We'll pick this up in a few weeks, right?"

Lucky for him, turns out they do.

* * *

Stiles, as it so happens, spends a good week worrying over if looking Derek in the eye when he visits for Thanksgiving break will be the start of an awkward weekend that will quickly snowball into tension too thick to be cut with samurai swords for absolutely no reason, because the second Derek steps past the threshold out of the November cold and his mother peppers him with kisses and Stiles' dad calls out a jovial hello from where he's stirring the stuffing, he catches Stiles' eye and his ears turn brilliantly red.

"Do you need help with your bags, Derek?" his mother asks when she catches sight of two bags laying at Derek's feet. "Scott can—"

"I'll help," Stiles says, springing off the couch, no longer interested in _Ferris Bueller's Day Off_ as it turns into white noise on the television for him even though Ferris is finally at the good part and is running past pools and barbeques to not be caught by his revengeful sister and Mr. Rooney. And Stiles loves _Ferris Bueller's Day Off_, so it's saying something when he offers to help drag luggage upstairs in favor of watching it.

Scott's mother ruffles his hair for his willingness to help and with that he grabs one of Derek's bags and all but bounces up the steps into Derek's room, left exactly the same it was a few weeks ago when they made out like rabbits in heat before Derek hightailed back to college.

He's barely dropped the bag, fully prepared to explain to Derek that he's in spirit much older and wiser than the sixteen-year-old sophomore he is and ready to rock his world, when he's thrown against Derek's bookcase, a good number of classic novels digging into the small of his back while Derek grabs him by the hair and presses their mouths together.

"A-ah, so I take it you haven't been swept off your feet by some pretty college girl in glasses since you've been gone, right? My dorkiness is still a turn-on for you?"

Derek covers his mouth with his own again when he starts rambling, no longer a shred of hesitance left in his touches like the idea of ravishing Stiles upon his return was enough to drum up a tightly-strung ball of hormones that unleashed Derek's inner sexual fiend while he was gone, using his teeth to bite and nip at Stiles' lip while his hands fist his hoodie. They kiss like they're much hungrier for each other than they are for the juicy turkey roasting downstairs, and Stiles wastes no time in hooking a frantic leg over Derek's hip and rutting against his crotch.

"God, you're so eager," Derek says breathlessly when he pulls back, lips looking so thoroughly kissed and shiny that Stiles doesn't even bother resisting the urge to swipe his tongue over his swollen lower lip.

"I was always this hyper. You've just come to appreciate it anew nowadays," Stiles quips, ducking his head into his neck to feel the burn of Derek's stubble on his temple and taste the salty groove of his collarbone. It feels much better this time than when he was drunk, nothing but foggy memories of having pliable muscles move underneath him lasting from that night. Stiles knows more than anything that those muscles and that mouth are definitely experiences he wants to memorize, starting with the tiny sounds Derek keeps letting loose and how sure his hands feel when he grabs Stiles by the hips.

"Your father would arrest me if he knew what his son was doing," Derek points out, and Stiles quickly shushes him with a few wet kisses and roaming hands exploring the sensitivity of his chest.

"Don't mention my _dad_, Derek," Stiles pretends that his father _isn't_downstairs teaching Scott how to make cranberry pie for traditional Stilinski Thanksgiving dessert and focuses instead on the way Derek's breath seems to fly from his lungs when he tweaks his nipples. Turns out, the distraction is more than enough to wipe any thoughts of his father imprisoning his new boyfriend—boyfriend?—for deflowering his purer-than-the-driven-snow-underage son from his mind.

Derek listens and that's all that is said on the illegality of what it is they're doing, instead pushing Stiles roughly against the bookcase once more, so roughly that a few photo albums sway precariously on their perch on the highest shelf.

"Ow, fuck, Derek, right against the dictionaries," Stiles groans when a few books dig persistently into his back, so Derek impatiently foregoes trying to do this vertically and tosses him on the bed like a lion ready to maul its afternoon meal. Stiles comes willingly and drags Derek down with him.

"Still can't believe I'm doing this," Derek murmurs incredulously on Stiles' neck while he fumbles with the button of his jeans and Stiles wrestles with Derek's shirt. "My brother's annoying little buddy. _God_, you used to annoy me. Never met a kid so determined to coerce me into playing hide and seek."

"Oh my god, Derek, shut up," Stiles begs, succeeding in wrenching Derek's shirt off and away to reveal the glory that is his naked chest while Derek shucks Stiles' pants down his knees and smirks at the sight of his Superman boxers. Stiles is about to remind him that he's about to sleep with him, superhero underpants and all, but then Derek shoves his hand down his boxers and grabs his half-erect member and strokes it.

Stiles denies that he whines—even though there's a very good chance that he does—and paws at Derek's shoulders at the sensational feeling of having someone else's hand, and out of all of the hands in the world, _Derek's_large and unyielding hands, slowly pumping him to release. He decides to follow suit and gathers the lucidity he has left to push Derek's pants and pesky boxers out of the way and squeeze the base of his erection, lazily curling toward his stomach, to the same rhythm that Derek's hand is moving away at on his own length.

It's a pretty great dick, Stiles thinks, which is saying something considering that he's more of a boobs type of guy when it comes to what he's more likely to ogle in a classroom. Apparently, he doesn't mind if it's Lydia's creamy cleavage or Derek's hard-as-a-rod cock that he's got in his hand, and decides to go with it while he's got Derek at his mercy.

Accurately, however, Stiles is more at Derek's mercy than vice versa. Thinking straight starts becoming a luxury of the past when Derek speeds up the pace of his hand and leaves trails of open-mouthed kisses on his jugular and his neck and the sensitive spot right behind his ear, thumb smearing drops of Stiles' precome on his shaft to slick the way for his palm. He does his best to reciprocate before the stars inevitably burst behind his eyelids, pumping Derek steadily with a shaky hand while he grabs his neck with his free hand and guides him to his mouth, sharing another sloppy kiss while they rock into each other's grips.

"Oh, _shit_, Derek, I can't—" Stiles gulps around a dry mouth when Derek speeds up his tempo even more and rubs the tip of his fingernail into the slit, heat coiling in his midsection. "Ready or not, here I come."

He comes right then, muffling his cry of bliss in the pillow conveniently perched by his head, trying his hardest to keep up the pace of his own hand. A second later, Derek's fingers join his own, interlacing their hands together to stroke steadily up and down his length, the hot weight of his member resting in both of their hands enough to intensify the waves of Stiles' pleasure. Derek comes with only five more strokes of their joined hands, letting loose a noise so sinfully suppressed Stiles is already prepared to orchestrate a replay of this whole event in the quiet solidarity of the backseat of his car so Derek can emit all the noises he pleases for Stiles' ears only without having to worry about eavesdroppers downstairs.

"C'mere," Derek mumbles after he catches his breath, cupping his cheek and kissing him, slowly and sweetly this time, while Stiles runs his hands through Derek's hair to keep him in place. Derek pulls back and gives him a small, barely even there smile, and Stiles feels like he's just solved one of the biggest mysteries in the world because he managed to make broody, grumpy, dark Derek smile.

The afterglow is ruined a moment later, however, by Scott screeching up the stairs, "Derek! Stiles! What the hell's taking so long?!"

* * *

So it turns out that sneaking around behind Scott's back is just as awesome as Stiles thought it would be.

Stiles idly wonders if he has something of a exhibitionist bone inside him considering that it's starting to become a habit for him to corner Derek in the hallway when Scott ambles downstairs to grab snacks so they can share a brief heated make out that always results in both of their lips turning rather swollen and their hair rather mussed, telltale signs of funny business that Scott really should catch but never does, or feel up Derek's thigh when their mother comes home early enough to make dinner and enjoy it with the whole family at the dining table. He wonders if it's because he enjoys getting a rise out of Derek, enjoys that fire of warning in his eyes that proves that he's both equally scared and turned on by the risk of Stiles giving him a blowjob in the bathroom.

Stiles has comes to terms with the fact that if Scott gets wind of this clandestine affair his friend is having with his brother he'll be letting Scott copy off his homework for life just to make up for his betrayal, mostly because he knows that there is no resisting Derek. What amazes him is that he finds that he actually likes Derek, because underneath his rather chilly exterior and hard glowers, he happens to be less whiny than his younger brother and less of a love struck fool, a stereotype which Scott is rapidly morphing into with the appearance of Allison Argent in his life. He teaches Stiles how to do his math homework whenever Stiles gets stuck and can prepare a pretty mean grilled cheese sandwich too.

He realizes pretty suddenly that aside from the amazing development in his sexual endeavors, Stiles appreciates the addition Derek makes in other aspects of his life. He likes the handjobs, he likes he making out, and he likes the grilled cheese, but under all of that he likes _hanging out with Derek_, a development that starts making Scott suspicious rather quickly. He tries to avoid the term _crushing_, mostly because he refuses to be identified as an elementary school girl, but Stiles isn't scared to admit his feelings. He has a crush on his best friend's brother.

The realization makes Stiles come to yet another grim epiphany: if Derek feels the same way—which Stiles can only assume is true considering that he hasn't yet been told to go play with the neighbor kids and leave Derek alone—then this isn't just a college-guy-experimentation phase that will ultimately fade into a nostalgic memory of his high school years. This might be a, dare he say it, real grown-up relationship. And that means it's time to get Scott adjusted to the idea of his best friend falling love with his brother.

"So, you know how you wanted to watch that one new action movie where Robert Downey Jr. loses his head this weekend?" Stiles slowly brings up at lunch the week before Derek visits for Christmas vacation around a mouthful of cafeteria breadsticks. Scott nods. "Well, I was thinking maybe Derek could go with us."

"What?" Scott demands. _Baby steps_, Stiles thinks, and tries to telepathically plead with his friend to be accommodating and open-minded.

"C'mon, dude, he's coming for Christmas and could use some holiday cheer from his little bro. Robert Downey Jr. will still get his head cut off no matter who comes with us, I promise."

Scott frowns and picks at his lunch tray. "He's such a killjoy, Stiles."

_Either we take him along, or I'm staying home so we can have sex in the back of my Jeep_, Stiles thinks resolutely on repeat, and then promptly erases that from his mind as he continues to focus on gently coaxing Scott in the direction he wants to steer him toward. _Be gentle. Don't scare him off. Like a deer in the forest._

"Just one movie, dude. You're not winning any Best Brother awards like this, Scott."

When Scott still whines and refuses, Stiles brings in the one weapon he didn't want to have to brandish: Allison, who naturally, thinks the idea of familial bonding is a great idea and insists Scott brings his brother.

Needless to say, Scott folds.

* * *

Stiles is wrapped up in his sheets watching _Saturday Night Live_ and scribbling random answers to his economics homework that he hopes Finstock will find enough humor in to grant him some credit when he texts Derek, who's programmed cleverly into his phone as _George Washington_ just because he knows Scott won't find it nearly as suspicious as seeing the name _Derek_flash on his screen if he accidentally comes upon such a scenario. Sometimes Stiles worries about how easy it is to con Scott, and sometimes he's just speechlessly grateful.

_asked Scott. you're coming with us to the movies next Saturday._He writes to Derek.

George Washington buzzes on his phone two minutes later. _That's surprising._

_had to bust out secret weapon aka allison. totally worth it. miss your grumpy face._

_I want to see you too, Stiles._Something like butterflies hatching or maybe a whole gang of hummingbirds flutters around in Stiles' chest, and he firmly blames the questionable leftover pizza his father left out on the stove for him as dinner for the sensations in his stomach.

_wearing anything sexy?_

_Stiles._

_what if I said I'm totally naked_

Two minutes later, George Washington calls him on his cell phone. Stiles picks up, snickering all the while.

"Stiles, I'm trying to study for my winter finals here," Derek's tinny voice reprimands from the other side of the phone. Without the added fright of seeing Derek's set jaw and angry white line of a mouth, it does little to scare Stiles off.

"And I'm trying to watch the new SNL skit, but I've decided that phone sex with you is more important than Fred Armisen."

"You want to have phone sex?"

"You don't?" Stiles asks, and feels the first stirrings of arousal in his groin that make him unbelievably glad that his father has the late shift at the station tonight. He tries to get the ball rolling. "Why don't you tell me what you're thinking about?"

For a moment, there's silence. Then, "You mean, besides the idea of you lying naked in your bed just waiting to be fucked?"

Stiles feels a full body shiver course through his limbs that catches him completely off guard. "Woah. Are you hiding a wild animal in that body of yours, Derek?"

"I think I can blame you for that," Derek admits. "I never thought so hard about grabbing a sixteen-year-old kid and swallowing down his dick before a few months ago when I caught you jerking off in my bathroom." Another bout of silence where Stiles hears Derek audibly swallow. "What were you thinking about when you did that?"

"You," Stiles says instantly, and decides to go for it and push his hand under the sheets and loosely grab his awakening cock, keening at the touch. "Couldn't stop thinking about you ever since you came back. Even though you acted like an asshole around me I couldn't help staring at your goddamn body. Fuck, Derek, I thought about you grabbing me and teasing me and making me beg for you to fuck me so many damn times."

A low pant sounds through the phone and Stiles catches wind of the sound of rustling fabric, like maybe Derek's abandoned his attempt to study and is now ridding himself off his pants. Stiles likes to imagine that maybe he's already hard just from the sound of Stiles' voice and the idea of playing out his fantasies, hard and needy all because of Stiles' dirty mouth.

"You'd want me to tease you?" Derek asks, and Stiles nods even though he knows he can't see him. "I could tease you."

"Tell me."

"_Stiles_," Derek murmurs, voice husky, like if he starts he won't be able to stop until he's barreled Stiles into a crashing orgasm. "I would finger you open until you'd be writhing for me to fuck you with my cock. Maybe I'd tease you before I would even finger you, maybe I'd just bite your thighs and suck your cock and lick over your hole until you'd push me back and ride me yourself."

Stiles groans at Derek's skill with imagery, squeezing his erection and bucking into his finger's frantic pumps. "Jesus, Derek. Are you touching yourself?"

Derek pauses, but he's breathing heavily and making the same soft noises Stiles has grown to love to hear escape from Derek's lips when he's stroking him to the brink. "Yeah."

"Thinking about me?"

"_Yeah_," Derek says. "Keep talking, Stiles."

"Shit, yeah, I will," Stiles says, only slightly amazed that there's someone out there who's actually asking him to keep running his mouth instead of warning to duct tape it closed for him. He lets his eyes flutter closed and his head hit the wall behind his bed, imagining that it's Derek who's stroking his cock and Derek who's leaning into his body. "Still want to have sex with you in Scott's bed, you know. It'd be so bad. Or maybe the kitchen counter, you could bend me over the dishwasher and just—just go to town."

"Are you a virgin, Stiles?" Derek suddenly asks, and Stiles feels his cheeks heat up.

"Well, yeah."

"So you'd be all mine?" Derek asks, his voice dropping a few octaves into the deep, growly territory that lets Stiles know that he's getting fired up past the point of no return. Whining, Stiles speeds up his hand and lets his free hand wander, thumb flitting over his puckered entrance and gently circling it. He's tried this before, in the shower, late at night in his bed, but now he's imagining Derek doing it, meticulously, gingerly, until Stiles is so ready he's begging.

"_Yeah_," Stiles confirms desperately, and cuts off on a broken cry when he comes, splattering his thighs and his sheets with his come and thighs quivering with the aftershocks. Across the line he can hear Derek, breathing still fast and uneven while he catches up, and not a minute later Derek comes too with the most delicious sound Stiles has ever heard wafting through the receiver.

"You okay, Stiles?" Derek says when he finally sounds like the oxygen has returned to his brain, and Stiles is so much better than okay it's not even funny.

"Okay? I'm _marvelous_," Stiles says, not even the prospect of three a.m. laundry to clean up the spots of his come from his sheets before his father notices darkening his spirits. "Except now I miss you even more."

Derek pauses again, like he's affronted by Stiles' clinginess, or maybe like he's actually touched by it. "I'll see you soon, Stiles," and then, as an afterthought, "and try not to jump me when you first see me if my brother's around."

* * *

"So how are your classes, Scott?"

Stiles is currently sandwiched in between the most awkward, uncomfortable brothers to ever exist, Derek forcing small talk and Scott bouncing around answering any of his questions with enthusiasm. Stiles knows that Scott and Derek are just some of those unfortunate siblings who never clicked when they were throwing blocks around a playpen together, possibly because of the age difference or maybe because they're practically complete opposites of the spectrum in every which way. Derek likes to be in control; Scott doesn't like to submit. Derek doesn't fawn over girls and fret over being romantic enough during formals; Scott's every waking minute revolves around the color of Allison's eyes. Derek spends forty minutes in the bathroom in the morning; Scott needs double.

Stiles is still convinced that with the right common ground the two of them could learn to gain a respect for each other past the required love that comes with being predestined with a brother, a respect that he's sure will have to be earned if he wants to maintain any hopes that Scott won't disown him when he ultimately breaks it to him that he's hot for his brother.

"Ummm. Okay, I guess. How's college?"

Stiles closes his eyes to block out the discomfort and occupies his hands with the bucket of popcorn in his lap while happy people, laughing people who enjoy each other's company, file into the theater around him. He's really only here for the gore and the possibly titillating plot—and maybe also the likelihood that in the darkness he'll be able to hook his ankle over Derek's under the gum-infested seats without Scott blatantly noticing the intimacy—and didn't sign up for any of this sibling rivalry, but he's willing to grin and bear it if it results in a positive step in the two of them bonding.

"Fine. Busy. How's mom doing?"

"She works a lot," Scott says, and that's the end of that. They drum their knuckles on their seat rests and both check their wristwatches like they're counting the seconds until the previews end and the movie starts.

"Heyyy, Derek," Stiles prompts when a whole minute full of wordless silence becomes his cue to speak up. "Did you know that Scott made lacrosse this year? Magically?"

"I didn't," Derek admits, and then cocks his eyebrow at Stiles. "Did you?"

"Uh, no," Stiles says. "But Scott's getting pretty good. He could probably use some of your work out tips, Derek."

"I don't _need_any tips with lacrosse."

"He's probably too busy keeping up with his grades, Stiles."

"Scott, my boy, you're gonna need lacrosse tips for the rest of your life," Stiles tells his left, and then promptly swivels to his right. "And Derek, I'm sure he wouldn't have so much trouble with his grades if you helped him with his homework."

He mediates for another ten minutes to nearly no avail before the theater thankfully begins dimming and the chatter dies down, and by the time Stiles realizes that even Robert Downey Jr,'s face can't salvage this terrible movie he's suffering through and Derek whispers in his ear for him to meet him in the bathroom, the blowjob he receives in the third stall by Derek's mouth, greasy from buttered popcorn and crazy talented, is definitely in order.

Stiles forgets all about the brotherly bonding flop that was the fiasco at the movie theater two days later when Scott cuts his and Stiles' homework session short in favor of a few texts from Allison alluding to the implication that she's up for a good few hours of making out in her room behind her parent's watchful eyes and his study session with Scott quickly turns into a date with Derek.

They start out just by talking about Derek's studies when Stiles wanders down the stairs from Scott's room after Scott darts out the house to meet Allison before dark, discussing what he's learned in his mythology class and what he thinks about doing after college. Stiles worries—only a little—that Derek will go on to bigger and greater things after he graduates to go be a philosopher in the depths of Norway or go fight crime with his glare alone in the shady parts of California, but Derek tells him about he's considering staying in Beacon Hills so he can stay close to his mother and keep watch over her if her job at the hospital stops paying all the bills one day. He even asks how Stiles feels about school, and what he wants to major in at college, and if he's considering taking over his dad's position as Beacon Hills sheriff in the future.

The fact that they talk so long—as nice as it might be—is probably what ends up in them having so little time for the sex.

They're making out on the living room couch, in broad view of anyone who marches past the front door, bodies too frantic and minds too lusty to even consider taking the time to relocate upstairs in the privacy of Derek's room. Stiles takes small pride in the fact that he seems to reduce Derek, a man who's in his early twenties and sufficiently done in his growing cycles, to an animalistic and hormonal replication of a seventeen-year-old.

"Missed you," Derek murmurs hotly on Stiles' lips, hands roaming under Stiles' pants to squeeze his hindquarters and trace the line of his ass. Stiles presses into him and all but rides his thigh when he brushes over his hole with a saliva-slick forefinger.

"Pants _off_, Jesus Christ," Stiles demands, momentarily getting off Derek to bodily throw his pants at the television until he's standing in nothing but his socks, Derek yanking him back on his hips and roughly abusing his neck with a demanding tongue. "Derek, _ah_, don't leave marks."

"Want to," Derek rumbles on his shoulder, rolling hips up into Stiles'. "Want to show everyone that you're mine."

"Everyone including your _brother_?"

"Fuck Scott," Derek says breezily, grabbing hold of Stiles' very-much-interested-in-the-situation erection and resuming his earlier task of rubbing patterns over Stiles' entrance. Stiles keens and ruts back against Derek's touch, strange but somehow not in the least invasive, until the tip of his finger slips inside. He tries to push into the touch, feel more, feel it slide even deeper, but the angle is awkward and Derek is impatient, so a second later he's flipped them over and pushed Stiles onto his stomach on the couch, spreading his ass cheeks and actually flicking his tongue down the curve of his ass.

"Oh _shit_," Stiles says, feeling like the luckiest high school in all the world right now, reaching behind him to pull Derek into a heated kiss, and so of course, that's when Scott's key turns in the lock and he announces his return home.

"What the fuck," Scott says faintly, looking so angry that it looks like he's about to have a tantrum right there on the floor and bang his fists on the carpet, and grabs the door handle for support.

* * *

Naturally, Scott takes most of his fury out on Derek. He's the older boy, he's the supposedly responsible college student, and he also happens to be the brother that takes everything away from Scott.

Stiles is listening to them yell from the safety of the kitchen where he's, thankfully, redressed and no longer naked in front of his best friend who hasn't seen him in his birthday suit since Scott's mother insisted on bathing them together when they first dabbled in mud slides when they were six, and in the middle of eating an old doughnut sitting in its box on the stove. He feels very much like he'd like to bend over the kitchen sink and throw up considering what the circumstances are, but he'll admit that sex makes him hungry, or at least, what _could_have been sex makes him hungry.

He wistfully thinks back to the days when Scott was never such a massive cockblocker, and realizes there were no such days.

"You're _so much older_! Do you realize how creepy that is?!" Scott all but roars from where he and Derek are dueling it out in Scott's room. Stiles battles between the two evils of eavesdropping into their fight and plugging his fingers to wallow in his own shame in silence. He goes for the former.

"Scott, I just don't see how this is any of _your_business."

"He's my best friend! Mine! You're not allowed to take him from me!"

"You're acting like a child, Scott."

"Stop talking to me like I'm four! _You're sleeping with my best friend!_"

Stiles rubs at his temples and thanks his lucky stars that he's not squatting in this kitchen with Scott and Derek's mother while she clicks her tongue and tries poorly to hide the fact that she's judging and probably making inferences that Stiles seduced her well-educated, totally-on-the-right-track eldest child and threw a bomb into the already shaky family dynamic. He hopes to God that he'll never have to face the wrath of their mother one day, even when he's over eighteen and totally legal or even over thirty and can no longer pass as a bumbling adolescent fool.

He looks at the plate of doughnuts, a few more crusty glazed pastries gazing at him imploringly so he can bury his worries in a sugar rush, but the sight makes his stomach churn. He braces his palms on the sink and listens once more to the third world war raging on upstairs.

"—_his_idea, Scott, I'm not forcing him to do anything with me."

"Are you seriously trying to tell me that my best friend would betray me just so he could score with you and have sex before I do?"

"This is not about you, Scott!"

"You don't even like each other, Derek!"

Stiles loudly hums _Somewhere Over the Rainbow_to himself and considers breaking up the fight himself, because at the end of the day, the blame does point directly back to Stiles in neon-lit arrows. He thinks maybe the idea of promising to buy Scott's lunch for the next three months and swearing to never make out in front of him might appease him into no longer yelling his throat hoarse at his boyfriend, or maybe offering himself up as a punching bag might work in Scott letting out some residual frustration, but a second later he realizes he's too late.

There comes a _thump_and a slew of curse words from upstairs, and a few seconds later Derek and Scott are walking stiffly down the staircase, a brilliant bruise sure to turn into a mottled purple by the end of the hour blossoming on Derek's eye and Scott nursing his knuckles. Stiles briefly wonders if the black eye was unavoidable collateral damage and considers tenderly touching the swelling flesh and offering an ice pack for the pain, but then decides that the best route for Stiles to take right now when Scott is clearly charged up with a generous amount of violence is to keep a wide berth away from Derek in Scott's line of vision.

Derek doesn't agree with this plan, however, as he proceeds to stalk up to Stiles, crowd up in his personal space, and murmur, "It's not as bad as it looks and I think I deserved it," and then, quite boldly, places a reassuring kiss on Stiles' forehead. Stiles waits, petrified, when Derek goes to retrieve a handful of ice from the freezer, for Scott to kick Stiles in the nuts for good measure too. He catches Scott's eye, who looks surprisingly uncomfortable in his own skin, and goes for a meek smile to gauge the mood.

"Hey, uh, Stiles?" Scott mumbles from the foot of the stairs. "Sorry if I always refused to hang out with Derek and give him a chance when you just wanted to make the two of us closer and, uh… I'm gonna be pissed about the fact that you're having sex with my brother for a while."

"Understood," Stiles says instantly, bouncing on the balls of his feet as if ready to dodge a strike even though he probably deserves it more than Derek's left eye did. "Total violation of the bro code. _To-tal_. Will not happen again. Won't chase after any other brothers you may or may not have."

"I just… wasn't really happy about having to share you," Scott mutters to the floor. He sounds crestfallen, like Derek is stealing Stiles away just like he stole all the good Halloween candy back a few years ago, and Stiles takes a bold step forward and wraps Scott in a much needed hug.

It should be awkward, considering that less than an hour ago he was naked on the couch with Derek's hands on his ass, but it turns out to be just the thing Scott needs to feel better about the situation, and they pat each other on the back for a solid few seconds before they pull back and survey each other.

"Uh… if you want to hit me now, that's okay, dude. Just don't go for the face, that's my moneymaker."

Scott actually cracks a small and rubs awkwardly at the back of his neck while Derek noisily rummages through the freezer to press a half-used pack of peas onto his bruise. "I don't wanna hit you, dude. Didn't really mean to hit Derek either, but… it sort of just happened."

"He'll heal up, the guy's built like Rambo," Stiles assures him, clapping him on the back. "And Scott, buddy, just think about it this way. If Derek and I ever move to Massachussets and get gay-married, you and I will be brothers. _Actual_brothers."

Scott cracks a wider smile. "Yeah, you're right."

"So… just keep Derek in one piece until then, okay?"

"Okay. Just… no making out in front of me and absolutely _no_having sex or stuff like that if I'm in the next room! This is non-negotiable!"

"We'll try," Derek says, rather sourly, from his spot in the kitchen, and Scott takes what he can get.

* * *

Amazingly enough, after that, everything improves.

The bruise heals fairly quickly with the help of icepacks and the firm decision among all three boys is that if anyone asks, especially their mother, Derek had a small mugging incident in the shady shopping district near campus that Scott or Stiles had absolutely no direct influence over. Scott doesn't apologize for punching Derek in the face and Derek doesn't ask for any such sentimentalities from his brother, like both of them have come to the grim truce that Derek probably deserved a good hit to the eye for not upholding his brotherly duty over the past few years and that now, if ever, is the time to start bonding.

The day after New Year's Eve, Stiles very much pretending that he and Derek didn't sneak out of their family's celebrations in order to make out behind the Stilinski garden shed in time for midnight last night, Stiles drives over to see Derek and Scott sitting around the coffee table playing Jenga in their pajamas without a care in the world like the apocalypse has hit Beacon Hills.

Stiles pockets his keys and tries not to bust out in a victory jig at the sight of Scott and Derek civilly agreeing with each other without Scott having to whine about Derek's domineering streak and Derek not walloping Scott over the top of the head every time he starts complaining about how tough his teenage life is, but he suppresses the urge and goes for a cheery wave instead.

"This is a little weird. Is one of you dying?" Stiles admits while he looks upon the scene in slight awe. Derek carefully pulls a block out from the middle of the tower and sends Stiles a glance of warning from his peripherals.

"Don't say anything. You might ruin it," Derek murmurs, precariously placing his piece on the top of the pile and watching as the tower sways ominously. "And I'm not just talking about the Jenga."

Stiles obediently shuts up and sits down when Derek pats the spot on the floor next to him, scooting into his side when Derek pulls him closer. He's still apprehensive about draping himself over Derek when Scott is watching with what is quickly becoming his default deer-in-the-headlight expression he wears whenever Derek kisses Stiles or Stiles makes an offhand comment about how sexy Derek is when he does his workout routine in the morning, but he supposes that exposure might be the only way that Scott will ever get to used to the new, truly bizarre paradigm that Stiles has brought into their friendship. He willingly molds himself into Derek's arm and successfully pulls a block out of the middle rows. The entire room tenses up with baited breath until he places it on the top. The tower survives.

"That was a close one," Stiles breathes into Derek's neck, reveling in the shiver that he feels course down his chest. He pokes Derek in the stomach right when he's reaching for a middle tile and watches as his hand unceremoniously crashes into the foundation and sends the blocks sprawling over the table and into everyone's laps. Scott laughs the most obnoxiously of them all.

"I hate you," Derek mumbles on Stiles' head.

"What did you just say?"

"He said he loved you, dumbass," Scott says while he scoops the remains of their Jenga tower into a pile of debris and tries his hardest not to look smug while Derek blushes a brilliant shade of red and his mouth takes a u-turn into a grim line. "What? If you're dating my best friend, I'm allowed to make fun of you."

Stiles laughs, pokes Derek in the stomach a few more times, and stops him from throwing rogue Jenga pieces at Scott's head.

All things considered, his best friend's brother is pretty cool.

* * *

_A/N: _This plot came to me on Saturday morning and wouldn't leave me alone until I finished it on Sunday night. Everybody enjoy!

Also, thank you to everyone who voted in the AfterElton Ultimate Slash Madness Poll! All hail Sterek, because as Jeff says, we are the "alphas of the fandom." Alphas assemble!

ALSO, this story has now turned into a series! The first timestamp of more to come is called "How to Date a College Graduate." That being said, there is no need to follow this story, as it is NOT being updated via chapters and is only a oneshot (as it says in the summary). Anyone interested in seeing more of this verse needs to check my list of stories as more is coming soon!


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